A modern integrated circuit (IC) sometimes includes diverse blocks of circuitry. The blocks of circuitry may have distinct or different origins. The designer of the IC may design and develop one block of circuitry, but rely on a vendor to design, develop, and supply another block of circuitry. The designer may save time, resources, and effort by using the vendor's circuit, rather than design and develop it itself. For example, an IC may include general digital logic as well as a memory. The designer of the IC may choose to design the general digital logic, but turn to a vendor for the memory.
Using blocks of circuitry with different origins, however, may pose certain challenges. Typically, the designer and the vendor may use different computer-aided design (CAD) tools, with diverse requirements, methodology, and output database formats and specifications. For example, the database for the designer's block of circuitry may have a different minimum feature size, grid system, and/or scale than the database for the vendor's block of circuitry and cause grid mismatch and undesired “snap to grid” in a merged database. Furthermore, the designer and the vendor may use different design rules and methodologies, thus complicating the verification process for the blocks of circuitry and the IC. A need exists for circuit verification without combining databases, and for and merging databases so as to preserve the integrity of the blocks of circuitry and of the overall IC.